Electric responsive device



Nov. 27, 1962 s. R. OVSHINSKY 3,066,203

ELECTRIC RESPONSIVE DEVICE Filed Nov. 6, 1957 5 Sheets-Sheet 1 3 Sheets-Sheet 2 l llil|l INVENTOR.

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ELECTRIC RESPONSIVE DEVICE Filed Nov. 6, 1957 3 Sheets-Sheet 3 Unite States 3,tl66,23 ELETR1 RESPUNSWE DEVECE Stanford R. @vshinslry, Detroit, Mich, assignor to Tann Corporation, Detroit, Mich, a corporation of Michigan Filed Nov. 6, 1957, Ser. No. 694,890 8 Claims. ill. 200-87) This invention relates to signal responsive devices, and particularly to devices which operate when one or more electric signals are applied thereto for completing circuits, performing work and the like.

The present invention pertains to devices having a ball or balls movable in a compartment for producing useful work, such as completing an electric circuit, striking a blow, changing the flow of fluid, pumping the fluid, accelerating a ball, inducing charges in a circuit and the like. A device with a pair of balls may be so constructed as to have one ball engage a contact in response to one signal and a second ball engage the first ball and a second contact in response to a different signal to thereby complete a circuit through the two contacts and the pair of balls. The reciprocation of a ball within a device may be employed for inducing a current in conducting turns of a coil associated with the device in response to the movement of a ball when made of magnetizable material or in response to charges thereon when a high potential voltage source reciprocates the ball and provides charges thereon. In a similar manner, the reciprocation of the ball by high potential voltage can charge a condenser to a degree at which a discharge will occur. The passage of the ball from one to the other end of the device or in an annular path may interrupt a beam of light passing thereacross to cut it off from a photoelectric cell. The movement of a ball within a device in reciprocation may produce the pumping of the fluid, sucking in the fluid when the ball moves in one direction, and discharging the fluid when the ball is moved in an opposite direction. The reciprocation of a ball from one to the other end of a device may change the flow of fluid from a central conduit to conduits at one or the other end of the device. The use of a high potential voltage to electrode positioned along a hollow tube may produce the increased acceleration of a ball and project it from the open end of the tube at high speed. A spiral path may be employed instead of the straight tube to produce a similar acceleration, the path terminating in a straight portion from which the accelerated ball will be propelled at high speed. A magnetic body may be provided for the valve which is attracted to one end of a housing by a magnet having an opposite polarity to complete a fluid path, and when a magnet of the opposite polarity is employed the body is repelled to thereby change the flow of fluid through a second path. Various signals may be employed for producing the operation of the device. A high potential voltage or a magnetic field may be utilized separately, or both the high potential voltage and the magnetic field can be employed simultaneously to control the desired operation of any of the devices.

Accordingly, the main objects of the invention are: to provide a device responsive to a known signal for producing an expected result; to employ a high potential voltage in the path in which a ball is to be reciprocated to have it strike an element which transfers the force to a point outside of the device; to provide a device having a pair of balls therein each movable into engagement with a contact and each other in the presence of two different predetermined signals; to provide a device with alternate high voltage fields for accelerating a ball and propelling it from the device at high speed, and, in general, to provide devices which respond to known signals for producing an expected result which is simple in construction, positive in operation, and economical of manufacture.

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Other objects and features of novelty of the invention will be specifically pointed out or will become apparent when referring, for better understanding of the invention, to the following description taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a sectional view of a switching device embodying features of the present invention;

FIG. 2 is a sectional view of a current generating device, showing another form of the invention;

FIG. 3 is a plan view of a generating device, similar to that illustrated in FIG. 2, showing another form which the invention may assume;

LFIG. 4 is a sectional view of a device, similar to that illustrated in FIG. 2, which is capable of storing charges;

FIG. 5 is a sectional view of structure, similar to that illustrated in FIG. 1, with additional controls embodied therein;

FIG. 6 is a sectional view of a device which produces an impact through a protruding portion thereof;

FIG. 7 is a sectional view of a device which is capable of operating as a pump;

PEG. 8 is a sectional view of structure, similar to that illustrated in PEG. 7, in the form of a valve for changing the flow of a fluid;

P16. 9 is a plan view of an element which increases the acceleration of a body so that it may be propelled therefrom at high velocity;

PEG. 10 is an enlarged sectional view of the structure illustrated in FIG. 9, taken on the line 10-10 thereof;

FIG. 11 is a sectional view of structure, similar to that illustrated in FIG. 6, showing another form of striking device;

FIG. 12 is a view of structure, similar to that illustrated in FIG. 9, showing another form of device for accelerating a body;

16. 13 is a view of structure, similar to that illustraded in FIG. 12, showing another manner in which the body may be accelerated;

14 is a plan view of a device for increasing the acceleration of a body and projecting it therefrom at high speed;

PEG. 15 is an enlarged, broken sectional view of the structure illustrated in FIG. 13, taken on the line 1515 thereof;

' MG. 16 is a sectional view of a device, similar to that illustrated in FIG. 8, showing another form which a valve and its operating device may assume, and

FIG. 17 is a sectional View of structure, similar to that illustrated in FIG. 5, showing a further form which the invention may assume.

Referring to FIGURE 1, a housing 20, made of insulating material, has a first set of terminals 21 and 22 for the application of a high potential therebetween, the terminals preferably being pointed so that the high potential voltage may readily discharge therefrom. A ball 23 is disposed within the bottom portion of a cavity 24 in a position to move toward and from the terminals 21 and 22. A pair of contacts 25 and 26 are disposed within the housing 2% adjacent to the end thereof so positioned that the contact 25 will be engaged by the ball 23 when the ball is moved to the right, as viewed in the figure. The contact 26 which is above the contact 25 will be engaged by a ball 27 when the ball is moved to the right in position to engage the contact and the ball 23. This produces a flow of current through a circuit 31 connected to the contacts 25 and 26. The ball 27 is attracted to one or the other end of the housing 20 by terminals 23 and 29 when a voltage is applied thereto. The balls 23 and 27 are preferably made of mag netizable material so that they will not only respond to an electrostatic field but also a magnetic field, depending upon what field predominates. Coils 36 are disposed at the ends of the housing, herein illustrated as being located about the terminals 21, 22, 255 and 29 and energized from a current source to produce a magnetic field to control the movement of the balls. Thus, the ball will respond to electrostatic or magnetic fields employed independently or in combination. The ball 23 or 27 when of magnetizable material has a coating of silver or similar good conducting material on the surface thereof so as to readily pass current therethrough. The halls may be similarly made of conducting material when responsive to an electrostatic field, such as silver or the like, and may be solid or hollow. Thus, the circuit will be completed across the contacts 25 and 26 when a high potential signal is produced across the terminals 21, 22 and 28, 29. Similarly, the circuit will be completed when a source of energy has been applied to one or the other coil 3% to have the balls 23 and 27 move to the right-hand end of the housing, as viewed in the figure, into engagement with each other and the contacts 25 and 26. Thus, the circuit will be completed only when a proper directional flow of high potential voltage occurs across the terminals 21, 22 and 28, 29 or a desirable flow of current has been applied to the coils 3t? separately or simultaneously to produce preponderant signals to position the balls. Either of the balls will be repelled from contact en aged position by a change in the signal produced by a change in the magnetic or electrostatic fields to break the circuit across the contacts 25 and 26. Thus, the circuit is completed only when a proper flow of current and/or voltage or both are delivered to the terminals and/ or coils of the device. It is to be understood that a pair of contacts 25 and 26 may be applied to the left-hand side of the housing connected in a circuit similar to the circuit 31. When two sets of contacts 25 and 26 are thus employed, a magnetic coil or high potential terminals can be mounted centrally thereof to hold one or both of the balls out of engagement with the contacts to thereby interrupt both of the circuits to the two sets of contacts 25 and 26.

In FIG. 2, a current generating device is illustrated embodying a housing 33 of insulating material having a chamber 34 in which a ball 35 is moved to the right and left, as viewed in the figure. A pair of terminals 21 and 22 at the end of the chamber 34 produces the reciprocation of the ball therein when a high potential voltage is applied to the terminals from a source 36 by the automatic change of the charge on the ball as it reaches the end of its travel. A plurality of turns 37 of conducting material, such as a copper wire, are provided about the chamber 34 in which a voltage is induced as the ball is reciprocated back and forth in the chamber 34 measured across the terminal ends 38 and 39 of the turns. The ball may be a permanent magnet so that magnetic lines of force will cut across the conducting coils and induce the flow of current therein. The ball also may be made of any material, conducting or in sulating, so long as it will retain a charge which it receives from the discharge across the path between the terminals 21 and 22. The charge on the ball is induced into the coils as the balls move back and forth, and since the charge is changed at the end of each cycle of movement, that is to say, at each end of its travel, an alternating current will be induced in the coil so that the potential at the terminal ends 33 and 39 will be an alternating In FIG. 3, a similar construction is illustrated, that wherein one or a plurality of the balls 35 are caused to travel in a circular path 41 by the terminals 21 and 22 to which a potential of opposite polarity is delivered, the terminals 21 receiving a potential of one polarity while the terminals 22 receive a potential of the opposite polarity. This causes the ball or balls to advance in the circular pathway 41 and cut across the coils 42 formed by a conducting wire Wound about the pathway to induce a current therein and a difference in potential across the terminals 43 and 4 This generating device is supported by insulating blocks 45 to which it is secured. The current is induced in the coils 4-2 by the charge on the ball or by a ball made of magnetic material which occurs in the same manner as referred to hereinabove with regard to the structure of FIG. 2.

In FIG. 4-, a device is illustrated similar to that of FIG. 3 but in the nature of a condenser wherein the insulating housing 33 has a compartment 34 in which a ball 35 is movable by a high potential voltage which is applied across the terminals 21 and 22 from a source 36. In place of the conducting coils 37, a plurality of turns of conducting and insulating sheet material 46 and 47 are wound about the compartment 34, with conductors 48 and 49 connected to the conducting material 46 at the inner and outer ends thereof. The conducting material may be a metal foil applied to one side of thin paper which is then wound into the coil, as herein illustrated. The width of the conducting material is less than the paper so that the side edges will not engage each other. The charges on the ball 35 will be induced onto the conducting sheet 4d and will collect and build up to a substantial capacity which may then be discharged across the terminals 433 and 49. This discharge occurs when sufficient charges have accumulated to overcome the air gap between the terminals 48 and 49. A small or large charge can be built up by using a single turn of the foil or a large plurality of such turns for the accumulation of the charges from the ball as it is reciprocated.

The device illustrated in FIG. 5 may respond to many signals applied thereto. The ball 35 may complete a circuit through contacts Ell at one end of the device through contacts 52 at the opposite end of the device. It may induce a charge in a plate 53 and its associated circuit, or current may be induced in the conducting coils 54 about the device and to a circuit in which it is connected. Thus, the device may be used to produce and to respond to a specific signal or to a combustion of signals, as referred to above. The ball is reciprocated by a high potential voltage applied to the terminals 21 and 22 and may be stopped by a magnetic flux from a coil 54 near the center of the device. An aperture or transparent window 51} is provided in opposite walls of the housing 33 through which a beam of light may pass to impinge upon a photoelectric cell which will be operated each time the ball interrupts the beam upon its passage from one to the other end of the compartment.

In FIG. 6, a striking device is illustrated to embodying an insulating housing as having a terminal 21 in one end and a ring terminal 57 in the other end supplied from a high potential source 36 to produce a high potential field across a compartment 34 having a ball 35 therein. In the lower end of the housing, as viewed in the figure, an impact element 58, such as a metal rod, is mounted in position to be struck by the ball each time it is reciprocated within the compartment 34. The striking force is transmitted through the rod 58 to the exposed end. Such a device will produce signals of various kinds. Sound can be produced by having the rod engage a gong, or an electric signal could be produced by striking a crystal of a known type.

In FIG. 7, another work performing device is illustrated which in this instance is for producing a flow of fluid, the device being in the nature of a pump. The device embodies a housing at having terminals 21 and 22 at opposite ends which produce reciprocation of the ball 35 when a high potential voltage from a source 36 is applied thereacross. The movement of the ball toward the terminal 21 opens a valve 6 2 and draws fluid from a conductor 63 to the interior of a compartment 64, while a valve 65 closes off a flow of fluid in the conduit 66. Upon the reverse movement of the ball toward the terminal 22, the valve 63 is closed and the fluid is forced into the conduit 66 past the valve 65 which is opened by the downward force of the moving ball.

In FIG. 8, a valve is illustrated which may be employed in combination the pump 70 or in any other fluid circuit, the valve embodying a housing 67 having an inlet conduit 68, and outlet conduits 69 and 70. A ball 35, which is magnetizable, is moved onto a seat 71 by the force of a magnet 72. This produces a flow of fluid from the conduit 68 into the device and out therefrom through the conduit 69. When the coil 72 is de-energized or reversely energized and the coil 73 energized to attract the ball 35, the ball will move onto the seat 74 and cut off the flow of fluid to the conduit 69 and produce a flow of fluid to the conduit 70. It is to be understood that a similar control of the ball to move onto the seats 71 and 74 may occur through the use of the high potential field when the fluid forces are not too great to provide a resistance to movement which the ball cannot overcome or when the fluid to the conduit 6%; is shut off and/or drained from the device. When a high potential voltage is used, the ball may be made of any material, but when coils 72 and 73 are utilized, magnetizable material is employed by the ball.

Referring to FIGS. 9 and 10, a novel use of the high potential field is illustrated, that for propelling a pellet at high speed from a tubular device. A ball '76 is disposed within an insulated tube 77 having a terminal 21 at one end with the opposite end open to permit the ball to be ejected therefrom. A plurality of rings 78 are provided about the tube, preferably spaced a greater distance apart from the left-hand end to the open right-hand end, as viewed in the figure. The rings 78 are energized from contacts 79 which may be evenly spaced along a tube 81 having a conducting strip 82 in the lower half thereof. A ball 83 completes a circuit between the strip 82 and the contacts 79, and in this manner progressively applies a high potential voltage to the rings 78 and immediately interrupts the applied voltage as the ball passes from one contact 79 to another. The movement of the ball is produced by the flow of high potential energy from a source 84 to terminals 85 at the opposite end of the tube 81. The terminal 21 and strip 81 are interconnected to a source of high potential 86. When the energy from the high potential source 84 is applied to the terminals 85, the ball 83 will quickly move from the left to the righthand end of the tube 81, and in so doing will complete a circuit between the electrode 21 and one of the rings 78 and instantly break such a circuit and cause the ball 76 to advance and become accelerated in the tube 77. The

' increased spacing of the rings 78 is in a ratio to apply the attractive energy of each of the rings to the ball to continuously accelerate the ball toward the open or righthand end of the tube 77. The ball is ejected at high speed from the tube without any retarding force being present since the applied energy is cut off by the advancement of the ball 83 before it detrimentally affects the movement of the ball 76.

In FIG. 11, a striking device is illustrated having a housing 88 containing a compartment 89 in which a ball 91 is housed. The ball is reciprocated within the compartment by a high potential voltage applied across the terminals 21 and 22 from a high potential source 36, not herein illustrated. The ball has a rod 92 extending downwardly there-from through a slot 93 in the wall of the housing 88 and a cylindrical striking element 94 is carried on the exposed end of the rod 92. As the ball reciprocates within the housing 88, the striking element 94 may engage a gong or other element to produce sound, may bridge contacts to complete a circuit, may operate a switch, or may do any other useful work at one or both ends of its travel in reciprocation.

In FIG. 12, a device is illustrated for propelling a ball in a similar manner to that of the device of FIG. 9. In this arrangement, the tube 77 has the rings 78 thereabout which in this instance may be evenly spaced. Conductors from a source of high potential voltage are connected to the rings in a manner to deliver progressively decreasing voltage thereto. This may be accomplished by the use of resistors 96 so that if, for example, 10,000 volts are applied to the left-hand ring, the voltage may be decreased in the order of 1000 volts for each ring progressively toward the negative ring 97 at the right-hand end of the tube. The ball is accelerated as it is moved by the high potential energy from the left to the right due to the decrease in potential progressively from the left to the right-hand end of the tube. This produces increased acceleration of the ball as it moves to the right so that it will have maximum velocity at the right-hand end of the tube when it is propelled therefrom. The same results would occur if the rings had a progressively increasing voltage applied thereto. The resulting acceleration to the ball would cause it to be propelled from the right-hand end with a high velocity.

In FIG. 13, another arrangement is illustrated for ejecting a ball at a high velocity. The tube 77 has the equally spaced rings 78 supplied with a potential of opposite polarity to alternate rings. Thus, the rings 78 have a positive potential applied thereto while the rings 79 have a negative potential applied thereto. The attractive and repellent forces thus produced within the tube between the adjacent rings will accelerate the ball as it is moved from the left to the right-hand end of the tube until it is propelled therefrom at a high speed.

Another interesting device for ejecting a ball is illustrated in FIGS. 14 and 15. A housing 102 has a spiral path 101 in which a plurality of electrodes 1032 and 104 are mounted. The electrodes 103 are connected in a circuit to have a positive potential, while the electrodes 104 are connected to have a negative potential. The energized electrodes produce attractive and repellent fields which accelerate the ball 105 disposed in a central aperture 106 in the spiral path to the outer straight end por tion 107 thereof from which the ball will be propelled in a straight line.

In FIG. 16, a proximity form of valve is illustrated, that wherein a housing 110 has a shiftable valve body 108 therein constructed as a permanent magnet, the right-hand end being the minus pole, the left-hand end being the plus pole. A bar magnet 109 is mounted on a shaft 111 for pivotal movement on a pair of standards 11?; for producing the shifting of the valve body 103. If the bar magnet 109 is rotated counterclockwise, the end 113 having a positive pole will attract the adjacent end of the valve body 108 which has the negative pole. When it is desired to shift the valve to the opposite position, that illustrated in the figure, then the end of the bar magnet 109 having the negative pole is moved adjacent to the end of the housing 110, the adjacent negative poles producing a repellent force which shifts the valve body 108 to the left, to the position illustrated in the figure.

In FIG. 17, a device is illustrated which produces rectification of a fiow of current from an AC. course. The device embodies a housing having elctrodcs 121 and 122 thereon which are connected to an A.C. circuit 123. Pairs of contacts 124 and 125 are mounted within the housing at opposite ends of the device to be bridged by a ball 126 which is reciprocated within the hollow interior 127 of the housing. When the ball is moved to the right-hand end of the housing, as illustrated in the figure, the contacts 124 are bridged and a circuit 123 from the circuit 123 passing through the contacts will pass current only during the time the ball bridges the contacts from a predetermined portion of the A.C. sinusoidal wave. When the ball is moved to the left to bridge the contacts 125, a circuit 129 will be completed from the circuit 123 and AC. current will pass from a prcdetermined portion of the sinusoidal wave. It is desirable to have the length of the hollow interior chamber 127 proportioned relative to the size and weight of the ball so as to have a direct ratio with the sinusoidal wave,

producing a movement to the ball in direct synchronisrn.

with the Wave since the ball will be immediately separated from the contacts after it moves into bridged relation therewith. When a proper ratio of length and weight ofthe ball has been established, the movement of the ball and the passage of the current through the contacts will be synchronized.

it may be desirable to retain the ball bridged across the contacts for a time so that a substantial amount of current is passed through each of the circuits 12S and 129 from opposite portions of the sinusoidal wave. A pair of coils l3 and 132 may be provided about the housing adjacent to the sets of contacts 124 and 125 and connected into the circuits E128 and 129 in a manner to provide a holding force for the ball at the opposite ends of the housing, first by the upper portion of the sinusoidal wave and then at the opposite end by the lower portion of the wave. A maximum force will occur at the top and bottom of the sinusoidal wave so that the holding force will be released before the reversal of the current in the wave form occurs and a substantial time will be had for pulsing unidirectional current in each of the circuits 12% and 129.

it is to be understood that a dielectric liquid may be employed within certain of the devices which could retain it for the reasons set forth in the above mentioned application. In place of such liquid, a gas, preferably of the inert type, could be utilized, sealed within the chamber in which the ball moves. The chamber could have the liquid or gas removed therefrom so that the ball would then operate in a vacuum. When the word ball is used throughout the specification and claims it is to be understood that any movable and chargeable means could be referred to and that such means could take any shape, form or material and not necessarily be a sphere.

What is claimed is:

1. In a signal responsive device, a housing, a chamber within the housing forming a passageway for a ball, a ball Within said chamber, terminals on the housing which produce the movement of the ball whena signal is applied thereto, a second chamber adjacent to said first chamber, a ball in said second chamber, coils on said housing adjacent to said second chamber which produce a magnetic field when energized to move said ball, and spaced contact means at one end of said device, both of said balls being movable to said one end of the device in response to predetermined signal means, said balls directly engaging one another and bridging said spaced contact means to complete a circuit thereacross.

2. In a signal responsive device, a housing, a chamber within the housing forming a passageway for a ball, a bail within said chamber, terminals on the housing which produce the movement of the ball when a signal is applied thereto, a second chamber adjacent to said first chamber, a ball in said second chamber, terminals on said housing adjacent to said second chamber which produce the movement of said second ball when a signal is applied thereto, spaced contact means at one end of said device one of which is engaged by said last ball to com plete a circuit through said first ball and the other contact means when both balls are at the end of the device in engagement with said contact means in response to predetermined signal means, and coils associated with said terminals energizable from a current source to produce magnetic fields whereby the balls are controlledby signals of electrostatic or magnetic fields separately or in combination.

3. In an AC. current rectifying device, a housing having an internal chamber, a ball reciprocable within said chamber, spaced contacts at least at one end of the housing, and terminals at opposite ends of the housing connected to an alternating current circuit, one branch of said circuit being connected to said contacts which, when bridged by said ball, cause -a unidirectional current to flow in said branch circuit. V

i 4. In an AC. current rectifying device, a housing having an internal. chamber, a ball reciprocable within said chamber, terminals at opposite ends of said housing connected to an alternating current circuit, pairs of spaced contacts at both ends of said housing, branches from said circuit being connected to said pars of contacts which are bridged by said ball when at one or the other end of the chamber, the direction of flow of current in the AC. source controlling the movement of the ball to one or the other end of the chamber causing it to bridge one or the other pairs of contacts permitting a pulsating uni.- directional iiow of current to occur alternately in both of the branch circuits.

5. In an AC. current rectifying device, a housing having an internal chamber, a ball reciprocable within said chamber, terminals at opposite ends of said housing connected to an alternating current circuit, pairs of spaced contacts at both ends of said housing, branches from said circuit being connected to said pairs of contacts which are bridged by said ball when at one or the other end of the chamber, the direction of flow of current in the AC. source controlling the movement of the ball to one or the other end of the chamber causing it to bridge one or the other pairs of contacts permitting a pulsating unidirectional flow of current to occur alternately in both of the branch circuits, and a coil about said chamber near each of said contacts connected in its associated branch circuit in a manner to retain the ball in position to bridge a pair of contacts to pass a unidirectional current therethrough for an increased length of time at both ends of the chamber.

6. In an AC. current rectifying device, a housing having an internal chamber, a ball in said chamber, a pair of spaced contacts at opposite ends of the chamber, terminals at opposite ends of the chamber connected to an alternating current source for causing the ball to move from one to the other end of said chamber each reverse cycle of alternating current, and a branch circuit from said A.C. source connected to said pairs of contacts through which unidirectional current is passed when the ball bridges a pair of said contacts.

7. In an A.C. current rectifying device, a housing having an internal chamber, a ball in said chamber, a pair of spaced contacts at opposite ends of the chamber, terminals at opposite ends of the chamber connected to an alternating current source for causing the ball. to move from one to the other end of said chamber each reverse cycle of alternating current, a branch circuit from said A.C. source connected to said pairs of contacts through which unidirectional current is passed when the ball bridges a pair of said contacts, and means for retaining said ball bridged across a pair of said contacts for a period of time less than one half of the A.C. wave cycle.

8. In an AC. current rectifying device, a housing having an internal chamber, a ball in said chamber, a pair of spaced contacts at opposite ends of the chamber, terminals at opposite ends of the chamber connected to an alternating current source for causing the ball to move from one to the other end of said chamber each reverse cycle of alternating current, and a branch circuit from said A.C. source connected to said pairs of contacts through which unidirectional current is passed when the ball bridges a pair of said contacts, the length of the chamber and the weight of the ball beingproportioned relative to the alternating wave cycle as to have the ball movement occur in exact synchronism with said wave cycle.

References Cited in the file of this patent UNITED STATES PATENTS (@ther references on foliowing page) Cole Mar. 18, 1941 Deakin Jan. 11, 1944 Irwin et a1. Feb. 13, 1945 Pridham Aug. 26, 1947 Berry Apr. 4, 1950 Gardner Mar. 6, 1951 Okay Dec. 8, 1953 Basilewsky Sept. 28, 1954 10 Fitch Aug. 9, 1955 Buckingham Jan. 24, 1956 Ohl Jan. 24, 1956 Parker Sept. 4, 1956 Valehrach May 6, 1958 Chilton et a1 Sept. 2, 1958 Ovshinsky Dec. 27, 1960 Ovshinsky Apr. 18, 1961 

